The present invention relates to automatic weapons of the type wherein the ammunition is fed automatically into the weapon, the ammunition being contained in or mounted in a metallic link, which link and ammunition cooperate to form a belt of ammunition, such that the removal of the round from the link belt permits the ammunition links to be disengaged and automatically discarded from the weapon. In this type of ammunition belt, the ammunition round and the links cooperate so as to form a chain wherein the round acts as the pintle of a hinge pivotally connecting adjacent links.
Weapons of the type to which the invention herein is directed, are exemplified by the M-60 machine gun, the XM 235 Squad Automatic Weapon and the M-85 machine gun. These weapons are characterized by ammunition contained in belts of approximately 100 rounds each. The design conserves weight and permits the assembly of the link ammunition with the use of relatively inexpensive metal links which are readily disconnected from the round upon firing and which are of small monetary value and therefore need not be collected after firing.
The links which are utilized to connect the ammunition rounds are of such a shape and character, that they conform closely to the outer diameters of the ammunition rounds and provide a secure means for linking ammunition rounds together. Additionally, the links align the ammunition rounds so that the ammunition belt is of uniform width, i.e. the bases of the linked ammunition define a single plane. This is accomplished by an extended retention tab on each link which seats in an annular indentation near the base of each round.
Before the intentive concept can be thoroughly understood it is necessary to understand the operation of a typical automatic weapon. When ready for firing, the operating group, which contains the firing pin, is in intimate contact with the ammunition round in the chamber. When the trigger is depressed, the firing pin within the operating group contacts the base of the ammunition round thereby causing ignition of powder within the round which results in the expansion of gases and the propulsion of a projectile (e.g. bullet) through the barrel of the weapon and to the target. Energy created by the expanding gases is utilized to cause the operating group to recoil or move rearwardly from the battery position. During the course of such recoil motion, the automatic feed mechanism of the weapon places the next round in position for displacement into the chamber by the operating group. The operating group reaches its rearmost position at which point, it has compressed the drive spring, thereafter, on the counter recoil stroke, moves the operating group forward into contact with the base of the ammunition round, removing the round from the link and into the chamber. The cycle of operation is completed as the operating group again achieves battery position so that the firing pin may make contact with the round, thereby initiating the ignition of powder once again.
The present state of the art requires the operating group to completely strip the ammunition round from the link belt on its counter recoil stroke. The energy for this counter recoil stroke comes totally from the drive spring which aids in absorbing the recoil energy associated with the firing of an ammunition round. The drive spring returns the operating group to its battery position and in the process, strips the round from the link belt. It is recognized by those skilled in the art, that a weapon system capable of fully automatic firing imparts tremendous forces upon the components of the weapon (e.g. drive spring, extractor, sear, buffer, etc.) Therefore, any assistance which can be given to these components or any resistance which can be removed or reduced will have a beneficial effect upon the life of the parts of the system.